when buy a multifamily property with tenants can I get them out?

[Miguel Garcia]

I'm planning to buy a multifamily property in Chicago, so I move in onto one unit and rent the other three to my family members, but property is already  occupied with tenants . Can I get the tenants to move out even if they have a previous lease? is it legal? what I have to do? I'm new in investing and I want to make sure I do the right thing. I will really appreciate your help. thanks